Manually operated switch with magnetically latched position



Allg 26, 1952 R. H. GooDRlcH 2,508,624

MANUALLY OPERATED SWITCH WITH MAGNETICALLY LATCHED POSITION Filed Sept. 18, 1948 3 Sheets-Sheet l A III] Aug. 26, 1952 R. H. GooDRlcH 2,608,624

MANUALLY OPERATED SWITCH WITH MAGNETICALLY LATCHED POSITION Filed Sept. 18, 1948 3 Sheets-Sheet 2 Aug 26, 1952 R. H. GooDRlcH 2,608,624

MANUALLY OPERATED S'NiITCH WITH MAGNETICALLY LATCHED PGSITION Filed Sept. 18, 1948 3 Sheetsf-Sheet 3 80 I!" Il v 2 /08 t mi Mmmm l m mm 17206722507? omHGUoCZH/'cv attorney Patented Aug. 26, n 1952 UNITED sTATss PATENT oFFIcE MANUALLY OPERATED SWITCH WITH MAGNETICALLY LATCHED POSITION Ross Harry Goodrich, Claremont, N H., assigner to rJoy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application September 18, 1948,'Serial No. 49,883

t y Claims. f 1 This invention relates to an electric switch. especially to a reversing switch for a direct cur- `rent motor.

In the operation of direct current electric motors, it is likely to be dangerous to try to open the armature circuit with the armature still rotating. The reason for this is` that the counterelectromotive force set upby the rotating arma- `ture is suii'icient 'to cause substantial arcing across the switch terminals if an attempt is made to break the circuit.

It is an object of this invention to provide a reversing switch in rwhich the armature circuit cannot be opened as long as the counterelectromotive force in the rotating armature is such as would cause destructive arcing if the circuit were opened. This and other objects are accomplished infa reversing switch in which the armature cir- 'cuit is made and broken by the engagement and disengagement respectively of two sets of contacts, one set being reciprocable relative to the other.l Relative reciprocation of the contacts is effected against a strong engaging spring by i means of a cam and cam follower which supplies the necessary mechanical advantage to overcome the spring. The reciprocable set of contacts is mounted on a rod which passes through a coil, thecoil being connected in the armature circuit.

A magnet armature adjusted at one end of the coil is hingedly mounted for movement toward the coil to close an air gap, and a cam mechanism is connected to cause engagement of a stop with an abutment on the rod upon movement of the amature `against the end of the coil. rAn indexing means is provided to assure alinement of the contacts for either forward or reverse operating position and to provide a third position in which one setA of. contacts lies between the other set of contacts.` The indexing mechanism includes a serrated member mounted on the switch casing and an indexing linger mounted for reciprocatio'n with the rod, andis so arranged that the reciprocable contacts may not be indexed when the contacts are engaged.

In the drawings:

Fig. 1 is a view in elevation of the indexing end of the switch showing the switch indexed so thatthe contactsof one set lie between the contacts of the other set. The cam mechanism is shown. in the position in which the two sets of contacts lie substantially in the same plane.

, Fig'..2 is a view in section substantially on line 2-1-ofFi`g. 1. l y

Flgisa view inelevation oi! the terminal end 'of the switch.

2 Fig. 4 is a viewin section on line 4--4 of Fig. 2. Fig. 5 is a view in section on line 5-5 of Fig. 2. Fig. 6 is a view similar, to Fig. 2 but showing the reciprocable contacts retracted out of the plane of the other contacts and axially displaced therefrom. y

Fig. 7 is a view in section similar to Fig. v2- but showing the reciprocable contacts in engagement with their cooperating contacts. 'As'shown in Fig. 7, indexing nger 18 occupiesthe notch 98 instead of the notch 94 as in Fig. 2. j

Fig. 8 is a view in section on line 8---8N of Figc?. Fig. 9 is a view in elevation of the indexing end of the switch showing the indexing nger inthe position it occupies when thecontacts occupy the relative position shown-in Fig. 7'.

Fig. 10 is a partial longitudinal section-along the line I0---Il'l of Fig. 9. l

Fig. 11 is'a view similar to Fig. 9 but showing the indexing finger inv the operating position which is the reverseof the operating position shown in Fig. 9. 1 y l Fig. 12 is a partial longitudinal sectionalong the line |2-l2 of Fig. 11. Fig. V13 is an enlarged end elevation view similar to that shown in Fig. 1'. Y Fig. 14 is a partial side elevation view of the switch with the parts -in the position shown in Fig. 13; 1 f

Fig.V 15 is another end elevation view similar to Fig. 13 but showing the cam follower herein in they position it occupies when the reciprocable contacts are retracted out of engagement with their cooperating contacts. Y

Fig. 16 is a sidel elevation view showing Ythe switch with the parts in the position shownvin Fig. 15; and Y Fig. 17 is a simple circuit diagramshowing how one set of contacts isconnected in the circuit of aD. C motor. A switch Ina'de according to this invention preferably includes a casing made-up of yan end member 2 having mounting ears 3, a side member 4,

and a 'second end member 6. The end member 2 is made of a magnetic material and the' end member 6 is made of a non-conducting material. The two end members andv the side member are held together by a plurality of threaded members 8.

A iirstset of contacts ID, I2, I4 and I6 is yield:-

ably mounted in the end member 6. Asis best seen in Figs. 10 and 12, each ofthe first set of contacts consists of a cupshaped engagingmem'- ber I8 which is preferably integral with av cone ductor rod 20 and'is mounted in a recess 22 in the second end member. Between the `end of nects the conductor rod 20v/ith a terminal.y

sists of a helical cam surface |04 and a rotatable cam follower |06. The cam follower |06 is integral with a hub |08, which is rotatable on bushing 16 by means of an integral handle 0. A thrust bearing, indicated generally at I2, mounted in the hub |08, contacts the inner face of block 86 land serves to force the block` vl'lei'tward to compress spring v| whenl handle `||0fis turned K counterclockwise, as seen in Fig. 1.

The end member 2 is formed with a toroidal recess ||4 in which is disposed a coil IIE. Coil ||6 The terminals are indicated generallyat 32, 34,

36 and 38, for the cooperating contacts I8. |2, I4 and I6 respectively. Each ofthe terminals is securely anchored by means of a bolt 40 held in the end member 6 by passing through an opening provided therein for the purpose, being held secure by clamping the end member 6 between a collar or ange 42 and a nut 44.

Avsecond set of contacts 46, 48, 50 and 52 is provided for engagement with the 'rst set. vIt is readily seen from the drawings that each of the rst set of contacts provides a concave cone which is engageable with the convex cone of the second set`of contacts. 'Each of the second set of contacts consists oi the aforesaid convex conical contact engagingmember 54 held in place in an insulating contact holder 56 byany suitable means, as, vfxorexample,by means of a thread von a shaft 58 integral with the contact engaging member 54 which in turn engages a threaded ange bushing'62.l Connecting conductor 64 electrically connectslthe contacts 46 and 52 by being clamped between one Vface of the member 56 and the undersideof the conical engaging member 54 in each case. Similarly -V the connecting conductor 66 electrically connects the contacts 48 and 50.

v The second setof contacts is reciprocable axial- 1y vrelative to the rst set of contacts by means off the insulatingk Contact carrier member 56 being mounted on an actuating rod 68.! As is readily seen in Fig. 2, contact carrying member 56 is clamped between a shoulder -10 and a' washer 'l2 by means of a nut 14. Actuating rod 68 is reciprocable in a bushing 1 6 inthe end member 2. Rod 68 is secured against rotation by the indexing iinger 18 heldin place in `one of the serrations of the serrated member 80. It will beseen that the serratedk member 80 is preferably integral with the end member 2. Finger 'I8 is yieldably mounted on a spring 82 by means of suitable fastening'members 84. Spring 82 is secured to a block 86 by means of a threaded member 88. Finger 18 is pivotally secured to block 86 by means of a pin 80. Block 86 may be held against rotation relative to rod 68 by a threaded member 90 which passes through the block and engages the Ysurface ofthe rod at its outer end.

' The serrated member isprovided with a plurality of notches 92, 84 and 86 to give the recipro- Ycable-'contacts three indexed positions, as will be tegral with the end member 2.' The spring |00 thus'biases the actuating rod 68 tothe right, as

seen in Fig-2. Rod 68 and its associated contact carrying member 56 may be reciprocated `axially t'o the' left, as seen in Fig. 2, by manual means.

Because of the strength of the spring |00, it is desirable to provide cam means with'a substantial mechanical advantage.y lThe cam meansV conductors C1 and C2.

will be connected in any suitable manner in the armature circuit, as will be readily understood by those skilledV in the art.

Ahinge member ||8 having a slot |20 is secured to the side of the end member 2, more specically to the shell |22 which forms the outer limits of the toroidal recess ||4. Screws |24 pass through the slot |20 and engage the shell |22 to hold the hinge member ||8 in position on the shell. The cooperation between the screws and the slot permits adjustment of the hinge memeY ber in a direction parallel to the axis of the coil H6.

A magnet armature |26 is hingedly mounted adjacent one end of coil ||6 by means of a second hinge member |28, being secured by any suitable means, such as screws |30. Hinge member. |28 cooperates with hinge member ||8 to form a complete hinge.

A cam |32 is adjustably secured to shell |22 by screws |34 cooperating'in a slot |36. `A roller cam follower |38 is rotatably mounted on a pin |48 in a latch member |42; see Fig.- 8. The latch member |42 is slotted, as shown at |44, andfa screw |46 cooperates-with the slot tomake the latch member slidable along the armature |26 in a direction which lies Vin a planeVv which includes the axis of rod |58y and is therefore substantially parallel to the axis of Vmovement of thesecond set of contacts 'as they reciprocate into and -out of engagement withthe i'lrst set of contacts. Two pins |48, one on each side of the latch member |42, serve as additional guide meansyto maintain the latch member |42 in proper alinement. The inner end ofthe latch member is provided with a semi-circular recess |58. As is best'seen in Fig. 7, thisrecess'ed end of thelatch member is adapted to be moved inward radially at one end of a reduced diameter portion |52 on rod 68 Yto cooperate with a shoulder |54.

A loop spring |56 bears against hinge member |28 and against the slidable latch 42'to bias the latter against the cam |32. Y i

Operation Reference is now had to the circuit diagram shown in Fig.' 17 in which contacts l0 rand, |4 of the above described first set of contacts are vconnected in the armature circuit of la direct current shunt eld motor M, and contacts |2 and |6 are connected to the two conduits L1 and L2' respectively of a direct current powerV source'.` The shunt iield F is lshown as being permanently connected to the powerV source by means ofjcon- For motor rotation in one direction, the second set of contacts will be so oriented as to cause connecting strap 64 to close a circuit between contacts and |2 and tocause .connecting strap 66 ,to close' a Vcircuit between contacts I6 and `|4. For rotationy in the Vreverse direction, the second vset 4of contacts 'Will Abefso 'xfm' h adt vthe operating positionshown lin'filig. 7. l"Witt-1Ythelsw-itchfparts'in the position shown in i close iacircuitfbetween vcorl'tatrts For a .detailed discussion of "the 1mechanical ning of thesw-i-tch, reference'wlill .first be that Vfiigure; the fiirst setfoi' 'contacts l and the second s et ofcont-actsare 'in conducting engagenient.'` Let `itr-iovrtze"assumed that 'lit is desired to reverse thefmotor( To accomplish that objectiv`e, vthe Ioperatorr lturns -the' V`motor controller to Nits oi position.' 'In many motor applications, 'the motor and the apparatus-driven thereby willicon- "tinue Ato coastl rather than to stop rotatingfim- "'mediatelyf" A lo-ng'ffasvmotor M is turning over v'at any? appreciablespeed, there is a substantial counter-E;

M. generated, andthis E. M, Fyis enough so that a damagingarc would be set up between'the two rsets-of -contacts if an attempt were made to disengage them preparatory to orienting themior. reverse operation-of the motor.

M. F. thus generated makes an electrocatedfisoua-s to cooperate with the shoulder |54 on'the rod v|58 to prevent disengagement .of the second set of contacts from the `first set .of con- `tactsgshould such disengagement be attempted.

It will be understood fromthe foregoing that the cam follower |38, latch Vmember |42 and the loop spring |56 constitute latch means toprevent A-disengagement of the -secondset of contactsfrom the first set.

It will be understood by those skilled in the art that the hinge member ||8 and the cam |32 may be adjusted along the axis of the coil IIB, in order to adjust the air gap in such a manner as to permit release of the latch means at a point where the counter-E. M. F. is not great enough to cause destructive arcing, should the two sets of contacts be disengaged. As will be understood by those skilled in the art, the loop spring |56, as well as the air gap, will determine what that E. M. F. amounts to. t

Let it now be assumed that the armature has slowed down to such a point that the counter E. M. F. is below the danger point, whereupon the latch means will assume the position shown in Fig. 2. The second set of contacts can then be moved out of engagement with the rst set of contacts by counterclockwise (as seen in Fig. l) rotation of handle l0, causing cam follower |06 to ride along the helical surface of cam |04, causing retraction of the second set of contacts from the rst set of contacts, after which the parts will occupy a position very much as shown in Fig. 6 (but note that the orientation of the second set of contacts in Fig. 6 is different from that shown in Figs. '7, 8, 9 and 10). With the rod 68 thus moved to the left as far as it can go, and spring being thus compressed a maximum, indexing finger 18 may be moved out of the notch 96 it occupies in Fig. 9 and into notch 92. The handle ||0 is thereupon moved clockwise to enable the spring |00 to reciprocate rod 68 to the right whereupon the second set of contacts engages the first set but in a new orientation, namely, the position shown in Figs. l1 and 12. The motor controller can then be turned "totheon posltiomandfthe motor will operate '1in na rllrection which lslthe 'reverse-UI its lopcmttun when the switch parts are in the position shown fIt will -be noted that the serrated kmember 80 v"isprovided''with .an intermediate notch 94. When fthe indexing iin'ger 18 Alies in notch Stand .It Vwill be noted that the notches Yin the indexvingl'ni'ember 8'0 are'sufiiciently deep, that theindexing finger cannot be moved out of anotch againsty the resistance of spring. 82 to attempt aireorientation `01E the second set of contacts .in

relation to the first set, Aunless the contactsv are 'rst :separated 'by *movement ofthe handle l`|`0 counterclockwise as seen in Fig. l,v Thus there `are provided two vinterloclrs against reversing of the switch until it is safe to do` so. The iirst interlo'ck is provided by the latch' means consistingA of the cam follower and latch M2 kcoop erating with the shoulder |54` on the reciprooable y'actuating rod 68. The second interlockiconsists of the indexingnger 18 lying in one of the deep lrnotches Vof the serrated member 80.

YIt willv be .found that among-the advantagesof a switch made according to this invention is the feature 'of safety whereby'the operator of the switch is safeguarded against dangerous arcing across' the contacts because -he will not` be able to operate the switch as long as the motor'armature is rotating atv such 'a speed vas could cause such arcing. Another advantage is the feature of orienting the contacts of the two sets in such a manner that the contacts of one set lie between the contacts of the other set, even though the position of the switch is such that the contacts of the two sets lie substantially all in the same plane. Other advantages will readily be apparent to those skilled in the art.

While there is in this application specically described one form which the invention may assume in practice, Iit will be understood that this form of the same is shown for purposes of illustration, and that the invention may be modiiier and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In an electric switch device having at least one contact movable to open and close an electric circuit and lock means to prevent movement of the contact, the combination of actuating means reciprocable to move said contact into circuit opening and closing position, a shoulder carried by the actuating means, electrical means energizable to prevent said contact movement, means responsive to energization of said electrical means and mounted for movement upon energiaation thereof, a latch member carried by said responsive means and movable into engagement with said shoulder, a cam follower connected to move the latch member into said engagement upon movement of the responsive means, and a cam positioned tol engage the cam follower and adapted to move the cam follower to effect the aforesaid movement of the latch member.

2. A switch device as in claim l, in which the responsive means is a platelike member hingedly mounted for pivotal movement, and the latch member is slidably carried by the platelike member.

3. A switch device as in claim 2, in which the 'cam follower'is carried by the latch member ad- 6.- Aswitch device as in claim 1, in which said contact is carried by the actuating means for reciprocation therewith into circuit opening and closing position; and in which the cam follower a roller carried by the latch member.

7. In'an electric switch device having at least one contact movable to open and close an electric circuitl and lock means to prevent movement of the contact, the combination of an actuating rod reciprocable 4to move said contact into circuit opening and closing position, a shoulder on the rod, an electromagnet energizable to prevent said contact movement, an armature adjacent one pole of the electromagnet and mounted for movement toward and away from said pole upon energization and deenergization of the magnet, a latch member carried by the armature and movable `into engagement with the shoulder on the rod, a

cam follower connected to move the latch member into' said engagement upon movement of the armature toward said pole, and a cam positioned to engage the cam follower and adapted to move lthe cam follower to effect the aforesaid movement of the latch member.

8. A switch device as in claim 7, in which the armature is a platelike member hingedly mounted for pivotal movement and having an opening for the actuating rod, and the latch member is slidably carried by the platelike member.

9. A switch device as in claim 8, in which the cam follower is a roller carried by the latch member, and in which said contact is carried by said rod for reciprocation therewith into circuit opening and closing position.

- 10. A switch device as in claim 7, in which the cam follower is a roller carried by the latch member, and in which said contact is carried by said rod for reciprocation therewith into circuit opening and closing position.

ROSS HARRY GOODRICH.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS Date 

